This section provides background information related to the present disclosure which is not necessarily prior art.
Many different types of vehicles are equipped with brake systems. Such vehicles may include, for example, heavy duty construction vehicles, tractors, trucks, and automobiles. One common type of brake system utilizes disc brake rotors that rotate with wheels of the vehicle. Such disc brake rotors generally comprise two parts, a hub portion that connects to the wheel and a brake disc that extends radially outward from the hub portion. Typical brake systems also include a brake caliper that applies a clamping force to the brake disc to slow the vehicle or to maintain the vehicle in a stationary condition. The brake caliper is installed over at least part of the brake disc. Each brake caliper typically includes two brake pads that are disposed on opposing sides of the brake disc. During operation of the brake system, the brake pads are moved into contact with the brake disc to apply the clamping force to the brake disc. The friction that is generated between the brake pads and the brake disc opposes rotational movement of the disc brake rotor and also produces heat as a by-product. Excessive heat generation in the disc brake rotor and other components of the brake system can contribute to brake failure, excessive wear, and can negatively impact brake performance, creating a condition that may lead to warping the disc brake rotor and/or decreased brake output torque.
Several attempts have been made to enhance heat transfer away from the disc brake rotor. For example, the brake disc in an internally ventilated disc brake rotor may be constructed of a pair of parallel discs that are connected to one another by a plurality of vanes. The parallel discs provide a braking surfaces that the brake pads contact. The plurality of vanes are circumferentially spaced apart from one another and are internally located within the disc brake rotor such that air can flow between the pair of parallels discs. In another example, cross-drilled disc brake rotors have a plurality of transverse holes drilled into the brake disc. In yet another example, slotted disc brake rotors have a plurality of shallow slots disposed along the braking surface.
In addition to disc brake rotors with the various cooling features described above, other disc brake rotor designs have been developed. One example is disclosed in U.S. Pat. No. 6,739,437, which issued on May 25, 2004 to inventors George A. Garfinkel et al. This patent discusses internally ventilated disc brake rotors that have curved vanes and surface ventilated disc brake rotors that have a plurality of external channels that extend radially across the brake disc. A concern exists regarding the plurality of external channels diminishing the strength of the brake disc, thus making the disc brake rotor more prone to mechanical and/or thermal failure.